[TYPO3-ect] RFC: Result Browser Service for lib/div - part 1

[Elmar Hinz]

1. Implementation as a service

The resultbrowser should be implemented as a service. Extensions that want
to display a resultbrowsser call this service. Different classes/extensions
can offer this service, so that the user can build a specific resultbrower.


2. Overview of the API

The calling extension communicates with the resultbrowser by setters and
getter methods. The setters set different values of the resultbrowser like
the total number of hits, the offset, the amount of hits per view,
parameters for the links, etc. The getters of the resulbrowser offer
strings of XHTML, that is the pager itself and at least one additional
status message.


3. Configuration of the resultbrowser

Because of the broad variant of possible resultbrowser implementations, it's
up to the resultbrowser itself, to manage necessary configurations.


4. Resultbrowser types: dropdown and link list

Example of dropdown:

------------
Hits 1  - 10
Hits 11 - 20
Hits 21 - 28
------------

Example of link list:

<< <  5  6  7  8  9  > >>

The resultviews can be selected out of a dropdown controll or by clicking on
links of a linklist. The dropdown list can have speaking labels that either
show the alphabetic range of the view like "ab - be" or the offset number
like "Hits: 50 - 60". As a link list we often find a list of links that
have a incremental view counter " 1 2 3 4 5 ...". Technically dropdown and
link list can have all of the named types as label, so that they can use an
identical API.

5. View offset (pointer) vs. result offset

The resultbrowser of tslib_pibase works with a parameter called "pointer".
It is the incremental number of the views. When such a link is clicked, a
list of results is queried and shown determined by the result offset and
the number of results per view. To determine the result offset the pointer
has to be multiplied with the numbers of results per view.

The evaluation from result offset to pointer and vice versa can be saved by
using the offset directly instead of the pointer. So that should be the
preferred technique. To also be usable for extensions of the tslib_pibase
type imlemantations are free to additionally support the pointer technique.